Ovens on the existing market are usually provided with timing devices, which usually work by countdown. When set time is ended, electronic buzzers or mechanical alarms on the timing devices will remind users to cut off gas sources by emitting alarm sound, and the ovens themselves cannot automatically cut off the gas sources. If the users do not hear the alarm and forget to cut off the gas sources, charring of food inside the ovens or fire and other potential safety hazards may be caused, in order to prevent accidents, the users must be in the vicinity of the ovens to hear the alarm, such that the users cannot be away from the ovens for a long time, resulting in inconvenience of use of the users.